What auto layout constraints need to be set so that an image inside a tableview cell expands to the width borders of the cell as in Twitter app?
I can not get it done and wonder which constraints and settings are necessary.
You should set Leading, Trailing, Top and Bottom constraints. Thus width will be resized according to the screen width and height will be set depending on the aspect ratio of the image, since your cell has dynamic height.
I just focused on the width constraints (leading & trailing), but you can also adjust the other constraints in a similar fashion for top & bottom.
Additionally, you may want to alter your image view to support this, but that will depend upon the image you use. I selected Aspect Fill to make sure it used the entire width. If your image is not properly sized though, this setting will crop the top & bottom of it.
Notice in the Add New Constraints window that the left & right boxes have a solid red line, which indicates they were selected.
You can adjust the imageView as needed to provide some padding if you want, such as was seen in your linked image as well. The method for setting constraints would still be the same though, just the values in the boxes would differ.
First, you should know that UIImageView in cell is not work as you think when you set the cell's height with 'UITableViewAutomaticDimension'.
If you set the 'height constraint' and change it's value will work.
So, set the 'leading', 'trailing', 'top', 'bottom' and 'height' constraints with your image view
And if your image downloaded, get it's size and do the math and set the 'height constraint' with it.
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat
{
return UITableViewAutomaticDimension
}
func tableView(_ tableView: UITableView, estimatedHeightForRowAt indexPath: IndexPath) -> CGFloat
{
return UITableViewAutomaticDimension
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell
{
let cell = tableView.dequeueReusableCell(withIdentifier: "list")
if let iv = cell?.contentView.viewWithTag(1) as? UIImageView
{
// this UIImageView.image(url: URL, placeHolder: UIImage, complete: (UIImage)->()) is my custom function.
// you can use SDWebImage's function
iv.image(url: URL(string: "http://imageurl")!, placeHolder: nil, complete: { (img) in
// calculate imageview's height
let ivHeight = (iv.frame.size.width * img.size.height) / img.size.width
// get height constraint and set the value.
for lc in iv.constraints
{
if lc.firstAttribute == .height
{
// this will change cell's height automatically
lc.constant = ivHeight
break
}
}
})
}
return cell!
}
Sorry about my bad english. :(
Related
I need to set UITableViewCell dynamic height based on it's content.
Here is my demo image:
In this to label which have dynamic content so based on that label content my cell height should change..
I get the constraint error. In this cell two UILabel is available and both have dynamic content size. (I already make the demo with auto resizing cell with only one label.) But in this cell two label are there. So error is xcode suggest me to give Y POS or Height to label, but I already set top constraints. (4 side constraints with label line set to 0 Zero) But still it's fails.
I also try with this code
self.tableView.estimatedRowHeight = 250.0;
self.tableView.rowHeight = UITableViewAutomaticDimension;
Here is my demo code
Look at the screenshot of my output. For both the labels , you should give all the four constrains and you have to change the heights of both the labels priority to 750 & set the hugging and resistance priority to 1000. Then you have to change the number of lines to 0 in storyboard
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return UITableViewAutomaticDimension
}
func tableView(_ tableView: UITableView, estimatedHeightForRowAt indexPath: IndexPath) -> CGFloat {
return 250
}
Add this code into viewDidLoad() method:
tableView.rowHeight = UITableViewAutomaticDimension
tableView.estimatedRowHeight = 44
In Swift 3, Use
func tableView(_ tableView: UITableView,estimatedHeightForRowAt indexPath: IndexPath) -> CGFloat {
return HEIGHT // Maximum cell height
}
In table view cell, Set dynamic height constraint to the text view (Greater than or equal) - Maximum text view height
I found the problem. After setting text to UILabel, it doesn't still set correct height frame to its content. In cellForRowAt, just add this:
//these make height frame both of labels became correct
cell.lbName.sizeToFit()
cell.lbAge.sizeToFit()
// update cell layout
cell.layoutIfNeeded()
Have a look at the UITableViewDelegate function tableView(_:heightForRowAt:). It’ll work in your case if you are able to calculate the height for a given index path.
I have a tableViewCell with a label inside that could be multiple lines tall. I've set the label's Lines property to 0. However, when I make the label's text have multiple lines the text gets cut off. Here's how I've set up my storyboard:
Does anybody know how I made the table's cells just tall enough to contain the labels within?
Setting Dynamic Cell height procedure
Pin the label from top and bottom. Please refer following Screen shot
Set numbers of line to 0 of the label as from property inspector of xcode, it can be done from code too please refer following screen shot
Implement delegates of table view mentioned below
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return UITableViewAutomaticDimension
}
func tableView(_ tableView: UITableView, estimatedHeightForRowAt indexPath: IndexPath) -> CGFloat {
return 50 // also UITableViewAutomaticDimension can be used
}
You are missing the bottom constraint from the label to the table view cell (as far as I can tell). In order to make autolayout know how large the height of the cell has to be, you need to supply those constraints.
In addition do not forget to provide the estimatedRowHeight to the table view. If that value is not given, automatic cell sizing will not work.
Senario A:
If I set the label content in cellForRowAtIndexPath, the cell correctly get resized.
Senario B:
If I change the text content in custom action in cell, the cell sized does not get changed.(I do call setNeedsLayout + layoutIfNeeded)
How to fix this?
EDIT:
1) I have set,
myTableView.estimatedRowHeight = 71.0
myTableView.rowHeight = UITableViewAutomaticDimension
2) I have correctly added auto layout constraints.
I was running into this issue, and my problem was that I was constraining the content to self (the UITableViewCell) and not to self.contentView (the contentView OF the cell). Hope this helps someone else who has built their cells all in code!
In my case, the cell's custom size was enabled:
After you change the text of the cell, just reload that particular cell or simply call mainTableView.reloadData().
To reload that cell-
//indexPath is indexPath of cell you just changed label of
mainTableView.reloadRows(at: indexPath, with: .automatic)
In my case, in the same cell I had an imageView in the top left corner with a "center vertically in container" constraint, and a "top space container" constraint.
Obviously to satisfy this two constraint the cell must have an height equal to:
(height of the imageView / 2) + (length of the top space container constraint).
This height is not enough to fit the label text, so my label had only 1 line visible.
After I have deleted the imageView top constraint all went to the right place, in my case i wanted the image to be centered, if the image had to stay in the top left corner I had to take off the "center vertically in container" constraint.
I hope this can help someone.
First of all, I don't specifically know what was your action on UITableViewCell. So, I assume I do that in UITableViewCell selection.
The below answer only work on iOS 9 and above
But, for some reason, it failed to do it in iOS 8 until it scroll. So, I will update the answer for iOS 8.
I have seen you have used UITableView's estimatedRowHeight and rowHeight at your project. So,
Please check the following
Make sure UITableView's estimatedRowHeight and rowHeight include inside viewDidLoad()
Make sure your UILabel lines set to 0
Make sure there is no constraints about height for your UILabel and let the constraints be like that :
If there are other component also included, make sure only bottom and top space constraints included or top space to container margin and bottom space to container margin.
Every time that you want to update the cell, you have to reload tableView no matter what your current situation will be.
So, don't say anything yet before you try this sample project, #Rikh answer still work. May be you are going in wrong direction. Here's the solution. Please do as I said steps by steps and let me know if that didn't work out. You might need to share your sample project which is causing.
Sample Demo - DynamicCellDemo
UPDATE for iOS 8 : update the following code for iOS 8 users
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
if #available(iOS 9, *) {
// do nothing
} else {
tblDynamic.reloadData()
}
}
what you can do is set the AutoLayout constraints for the label in present in the cell from all the sides that is from Top, Bottom, Leading and Trailing. Then add the following UITableViewDelegate method to your class.
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return UITableViewAutomaticDimension
}
func tableView(_ tableView: UITableView, estimatedHeightForRowAt indexPath: IndexPath) -> CGFloat {
return 500
}
This will do the job. As now content in table view cell automatically adjusts the height of the cell.
Try this if it works:
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return UITableViewAutomaticDimension
}
func tableView(_ tableView: UITableView, estimatedHeightForRowAt indexPath: IndexPath) -> CGFloat {
return UITableViewAutomaticDimension
}
Add the following in your viewDidLoad()
-(void)viewDidLoad{
[super viewDidLoad];
tableView.rowHeight = UITableViewAutomaticDimension
tableView.estimatedRowHeight = 140
}
So I have been trying to adjust the size of my tableView Cells according to the size of an image that I get from an API call that I make.
http://i.imgur.com/yUmISx1.png
The images that I get are in a 5:4 ratio.
What i've done in the screenshot is put a fixed height under
override func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
let viewWidth = self.view.frame.size.width
let imageHeight = (viewWidth * 5) / 4
return imageHeight
}
(I've ignored small things like cell Paddings and stuff)
Even though the image doesn't look too bad, i'm not happy with what i've done. I have also tried
func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
if image != nil {
return image.size.height
} else {
return DEFAULT_HEIGHT
}
}
Which gives me a cell size where the image's height is being stretched. What is the correct way to do what i'm trying to achieve?
EDIT: I wanted to find a way so that the image automatically adjusts itself.
For example,
Right now, the images that I receive from the backend are in the ratio 4:5.
Hypothetical situation if they change it to a 1:1 ratio, I would want it to adjust itself. Any suggestion?
Also, my storyboard is going bonkers when i add the aspect ratio.
TIA!
Why don't you use Autolayout for your cell, put the ImageView inside the cell and give it trailing and leading constraints of 0(or your margin) and an aspect ratio constraint of 5:4?
I have a UITableView with custom UITableViewCells, each has a UIButton inside. I'm setting buttons' titles from an array, so the size of the buttons change according to the title. I need to return correct height based on the inner button's size in heightForRowAtIndexPath event.
Since I'm using auto layout, I've created an outlet for the button's height constraint and I'm updating it in the cell's layoutSubviews() event like this:
class CustomCell: UITableViewCell {
/* ... */
override func layoutSubviews() {
super.layoutSubviews()
self.myButton?.layoutIfNeeded()
self.heightConstraint?.constant = self.myButton!.titleLabel!.frame.size.height
}
}
Then I return the height based on the button height and top-bottom margins like so:
func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
var cell = tableView.dequeueReusableCellWithIdentifier("CustomCell") as! CustomCell
cell.myButton?.setTitle(self.data[indexPath.row], forState: UIControlState.Normal)
cell.bounds = CGRectMake(0, 0, CGRectGetWidth(tableView.bounds), CGRectGetHeight(cell.bounds))
cell.setNeedsLayout()
cell.layoutIfNeeded()
return cell.myButton!.systemLayoutSizeFittingSize(UILayoutFittingCompressedSize).height + (cell.topMarginConstraint!.constant * 2) /* top-bottom margins */ + 1 /* separator height */
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
var cell = tableView.dequeueReusableCellWithIdentifier("CustomCell") as! CustomCell
cell.myButton?.setTitle(self.data[indexPath.row], forState: UIControlState.Normal)
return cell
}
On the first launch, there seems to be no problem. However, after I begin scrolling, then the height of some rows seem to be mistaken. When I get back to the top, I see that previous cell heights get to be broken as well.
When I googled for similar problems, issue seems to be about reusable cells, though I was unable to find another way to calculate the height. What can be done to reuse cells correctly or getting the correct height, perhaps by another method?
More info and source code:
Constraints set by IB like this:
Here's the cells on the first launch:
After some scrolling:
Full code of the project can be found on Github.
According to this
Configure tableView as
func configureTableView() {
tableView.rowHeight = UITableViewAutomaticDimension
tableView.estimatedRowHeight = 160.0
}
Call it on your viewDidLoad method
Than configure your uibutton height constraint to be greater then or equal.
Override func tableView(tableView: UITableView, estimatedHeightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat where you can place your estimation height code
First off, it's better if you perform constraint updates in func updateConstraints() method of UIView. So instead of
override func layoutSubviews() {
super.layoutSubviews()
self.myButton?.layoutIfNeeded()
self.heightConstraint?.constant = self.myButton!.titleLabel!.frame.size.height
}
I would do
override func updateConstraints() {
self.myButton?.layoutIfNeeded()
self.heightConstraint?.constant = self.myButton!.titleLabel!.frame.size.height
super.updateConstraints()
}
Note that you should call the super implementation at the end, not at the start. Then you would call cell.setNeedsUpdateConstraints() to trigger a constraint update pass.
Also you should never directly manipulate the cell bounds the way you are doing in heightForRowAtIndePath: method, and even if you are completely sure that manipulating directly is what you want, you should manipulate cell.contentView's bounds, not the cell's bounds. If you are looking to adjust the cell height dynamically with respect to the dimensions of the content, you should use self sizing cells. If you need to support iOS 7, then this answer tells you how to achieve that behaviour with autolayout only (without touching the bounds etc).
To reiterate the answer, you should do:
func viewDidLoad() {
self.dummyCell = CustomCell.init()
// additional setup
}
func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
self.dummyCell.myButton?.setTitle(self.data[indexPath.row], forState: UIControlState.Normal)
self.dummyCell.layoutIfNeeded() // or self.dummyCell.setNeedsUpdateConstraints() if and only if the button text is changing in the cell
return self.dummyCell.systemLayoutSizeFittingSize(UILayoutFittingCompressedSize).height
}
Please know that the answer I linked to outlines a strategy to get the cell height via autolayout, so only writing the code changes I proposed won't be enough unless you set your constraints in a way that makes this solution work. Please refer to that answer for more information.
Hope it helps!
First of all, remove the height constraint of button and bind it to top and bottom with cell.
Then, in your cell' height, calculate height of the text based on the width and font of button. This will make the cell's height dynamic and you wont need height constraint anymore.
Refer the link below to get the height of text:
Adjust UILabel height to text
Hope it helps. If you need help further or understanding anything, let me know.. :)